When to apply crabgrass preventer in Maryland?
By LawnYear editorial team · Published · Updated Windows are read from the extension publications listed under Sources; the dates are approximate.
The answer
Preemergent weed control for tall fescue in Maryland runs from Mar 1 to Apr 30, per University of Maryland Extension (2026). Preemergent herbicide in March to April; it may need more than one application, and the page says not to use one where you plan to seed. Whole months shown.
Full calendar: Maryland lawn care calendar · Tall fescue in other states · Lawn schedule by ZIP
Approximate dates for your state. Check with your local cooperative extension office before you act.
All Maryland windows for tall fescue
The Maryland calendar on this site lists seeding Aug 15 to Oct 15, fertilizing Aug 15 to Oct 31, Nov 1 to Nov 15 and Apr 1 to May 15 and weed control Mar 1 to Apr 30 for tall fescue.
Where the dates come from
University of Maryland Extension: Lawn Maintenance Calendar (2026); seasonal timing for tall fescue, fine fescue and zoysia, page updated March 16, 2026. Gives seasons and months, no nitrogen rates. Read on 2026-10-30.
What to check for Maryland
The weed control dates for tall fescue above (Mar 1 to Apr 30) apply to Maryland as a whole, so the north and south of the state are not told apart. Where the source names only a month, the window runs from the first to the last day of that month.
Other grasses in Maryland
For fine fescue, the Maryland calendar gives Mar 1 to Apr 30 for weed control.
Weed control tall fescue in other states
- Virginia: Mar 1 to Apr 30 and Aug 15 to Sep 15, per Virginia Cooperative Extension (Virginia Tech), 2025.
- North Carolina: Mar 1 to Mar 31, per NC State Extension (2021).
- Georgia: Feb 1 to Mar 31, per University of Georgia Cooperative Extension (2023).
- Pennsylvania: Mar 15 to May 15, per Penn State Extension.
- Ohio: Apr 1 to Apr 25, per Ohio State University Extension, Lake County (2007).
- Kentucky: Apr 1 to Apr 30, per University of Kentucky Cooperative Extension Service (2014).
- Indiana: Apr 1 to Apr 30 and Oct 1 to Oct 31, per Purdue University Cooperative Extension Service (1998).
- New Jersey: Apr 1 to Apr 30 and Jun 1 to Jun 15, per Rutgers Cooperative Extension (NJAES), 2019.